Voltage-supply circuit and method for providing a circuit with a supply voltage

A method for providing a circuit with a supply voltage using a regulation transistor, which is connected between a first supply-voltage feed line and a second supply-voltage feed line, and which is formed to regulate, based on a first supply voltage present on the first supply-voltage feed line, a second supply voltage present on the second supply-voltage feed line, the regulation transistor providing a supply current the second supply voltage, the method comprising:

• determining whether the regulation transistor is at a low operating point, based on information that is a measure for the supply current, the regulation transistor being at a low operating point when the supply current is below a predetermined value,
• wherein, at a supply current below the predetermined value, the second supply voltage temporarily falls in amount below a predetermined permissible minimum voltage value below which reliable operation of a circuit provided with the second supply voltage is not guaranteed if the current present on the second supply-voltage feed line rises by a predetermined current amount within a predetermined period;
• and
• preventing, starting from the low operating point, a rise of the supply current by at least the predetermined current amount from occurring within the predetermined period.

A voltage-supply apparatus, comprising:

• a regulator means, which is connected between a first supply-voltage feed line and a second supply-voltage feed line, for regulating, based on a first supply voltage present on the first supply-voltage feed line, a second supply voltage present on the second supply-voltage feed line, and the regulator means for providing a supply current to the second supply-voltage feed line;
• an operating-point determination means for determining, based on information that the operating-point determination means is a measure for the supply current, whether the regulator means is at a low operating point at which the supply current is below a determined value,
• wherein at a supply current below the determined value the second supply voltage temporarily falls in amount below a predetermined permissible minimum voltage value below which a reliable operation of a circuit provided with the second supply voltage is not guaranteed if the current present on the second supply-voltage feed line rises by a predetermined current amount within a predetermined period;
• and
• a prevention means for preventing staffing from the low operating point, a rise of the supply current by at least the predetermined current amount from occurring within the predetermined period.